Single Ply vs. Double Ply

 I have a question:  I have been led to understand that you must knit or crochet with a plied yarn.  Is there any reason I can knit or crochet with a single ply?  I have 20 balls of single spun yarn that I spun.  Should I go ahead and ply these balls?  They were spun with the S twist.  I am fairly new to spinning so I don't know all the terms.  I am also not sure how many twists to the inch in my yarn. 

 I'm not a spinner so i don't know about the different spinning techniques, but in sock yarn articles they stress that plied yarn is stronger and will wear better, especially if tightly spun. I'm not sure this applies when it comes to scarves and such, but for hard-wearing items consider "the ply factor" lol

It is possible to knit with singles though as the person above me mentioned, they don't wear as well as plied yarns. Do be aware that because the twist isn't balanced with a ply if you knit with a single your stitches will lean to the side like |/ or \| (depending on S or Z, or Z or S, I can't remember which way the twists lean) rather than be a balanced \/. I suspect it makes less difference in crochet, but I haven't tried it.

I've been spinning a fair amount of high-twist laceweight singles lately, to have fun knitting lace with.  They'll lay flat since I plan to knit garter-stitch lace with them; the alternating rows of knit and purl on the face of the knit fabric stop them from skewing.  So, garter stitch is a great method to use with singles for knitting.  One of my local friends is an avid spinner-crocheter, and she spins singles to crochet with quite often. Her crochet vest is lovely, with granny square borders and single crochet body. I don't see any misbehavior in the fabric from her use of singles.

If you'd like stronger wear from the singles, you can knit a tighter fabric than the yarn thickness dictates -- go down a needle size or two so that the knit fabric is very dense. This helps add strength to the surface of the knit fabric, and can also make a super-cushy knit hat

 I have knit up quite a few hats and mittens from singles. They tend to pill a bit more. But, you get great stitch definition from singles. My advise it to experiment with your yarns. Sometimes you find they do amazing things you didn't know would happen. But for sure use the yarn you spun up. When you knit it, see how it drapes or how bouncey or tight the cloth you make is. They more you spin and knit your handspun, the more you learn from it and how it reacts. And each breed has a characteristic to its finished product, as does they way (worsted, woolen etc, see this most recent issue of Interweave's Spin Off for a good article with pictures that identify worsted and woolen)you spin it. So, give your own yarns a whorl (pun intended) and be proud of them and wear them proudly.

I use singles to knit with all the time, especially for hats, which don't wear out quickly for me, compared to socks and sweaters- the pills really show up on sweaters for me.

Carolyn:  Sure you can knit and/or crochet with singles. Look at Lopi or Brown Sheep's Lamb's Pride yarns; they are each commercially prepared singles. Or get ahold of any of the articles in Spin-Off or Interweave Knits on/about/by Kathryn Alexander - she spins 'energized' singles and uses them in her patterns. One of the most helpful finds for me was the "Twisted Sister's Sock Workbook" by Lynne Vogel which discusses dyeing your own colors, spinning the yarn (on a hand spindle!),  and how to use the resulting yarn -as singles or not- to knit your own socks. Very encouraging and clear - I knit a pair of socks directly off the spindle using the book; my sister says she never gets cold when she wears them.  So have fun and experiment and show us the results!      Kate